From mboxrd@z Thu Jan  1 00:00:00 1970
From: Bruce Richardson <bruce.richardson@intel.com>
Subject: Re: [PATCH] mk: fix scope of disabling AVX512F support
Date: Thu, 20 Dec 2018 11:29:17 +0000
Message-ID: <20181220112917.GA14024@bricha3-MOBL.ger.corp.intel.com>
References: <20181219192904.61934-1-ferruh.yigit@intel.com>
 <1772993.ZpFq8iN2Ki@xps>
 <0ee900c3-57eb-9c89-0b0f-7f724c095d6b@intel.com>
 <1618982.fK5yx7iQXf@xps>
 <859da395-a0fd-2231-6d07-b20a0146ff15@intel.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Cc: Thomas Monjalon <thomas@monjalon.net>, dev@dpdk.org, stable@dpdk.org,
 Tom Barbette <barbette@kth.se>, Yongseok Koh <yskoh@mellanox.com>,
 Konstantin Ananyev <konstantin.ananyev@intel.com>
To: Ferruh Yigit <ferruh.yigit@intel.com>
Return-path: <dev-bounces@dpdk.org>
Content-Disposition: inline
In-Reply-To: <859da395-a0fd-2231-6d07-b20a0146ff15@intel.com>
List-Id: DPDK patches and discussions <dev.dpdk.org>
List-Unsubscribe: <https://mails.dpdk.org/options/dev>,
 <mailto:dev-request@dpdk.org?subject=unsubscribe>
List-Archive: <http://mails.dpdk.org/archives/dev/>
List-Post: <mailto:dev@dpdk.org>
List-Help: <mailto:dev-request@dpdk.org?subject=help>
List-Subscribe: <https://mails.dpdk.org/listinfo/dev>,
 <mailto:dev-request@dpdk.org?subject=subscribe>
Errors-To: dev-bounces@dpdk.org
Sender: "dev" <dev-bounces@dpdk.org>

On Wed, Dec 19, 2018 at 08:53:34PM +0000, Ferruh Yigit wrote:
> On 12/19/2018 8:28 PM, Thomas Monjalon wrote:
> > 19/12/2018 21:20, Ferruh Yigit:
> >> On 12/19/2018 7:58 PM, Thomas Monjalon wrote:
> >>> 19/12/2018 20:29, Ferruh Yigit:
> >>>> AVX512 was disabled for GCC because of Bugzilla issue 97 [1],
> >>>> the GCC defect submitted for the issue [2] highlighted that this is
> >>>> a known binutils version 2.30 issue.
> >>>>
> >>>> Narrowed the scope of no-avx512 to the this specific binutils version.
> >>> [...]
> >>>>  # disable AVX512F support of gcc as a workaround for Bug 97
> >>>>  ifeq ($(CONFIG_RTE_TOOLCHAIN_GCC),y)
> >>>> +ifneq ($(filter 2.30%,$(LD_VERSION)),)
> >>>>  MACHINE_CFLAGS += -mno-avx512f
> >>>
> >>> I think we should print a warning here.
> >>> There is a function $(warning) or $(info) for such case.
> >>
> >> I can add but it prints warning per component, so it prints a lot.
> > 
> > I think we can choose to print only when compiling EAL
> > by checking $(findstring eal,$(lastword $(MAKEFILE_LIST)))
> 
> Thanks for hint, I will use it.
> 
> > 
> > One more comment: it would be good to have this fix with meson too.
> 
> Agreed, only I am not quite sure how to fix it in meson.

One suggestion, but the snippet below in main meson.build file, and put the
printing of a message in one of the EAL meson.build files.

/Bruce

ldver = run_command('ld', '-v').stdout().strip()
if ldver.contains('2.30')
     # take action here
endif